27 lines
596 B
C
27 lines
596 B
C
|
/*
|
||
|
|
* linux/fs/ext3/bitmap.c
|
||
|
|
*
|
||
|
|
* Copyright (C) 1992, 1993, 1994, 1995
|
||
|
|
* Remy Card (card@masi.ibp.fr)
|
||
|
|
* Laboratoire MASI - Institut Blaise Pascal
|
||
|
|
* Universite Pierre et Marie Curie (Paris VI)
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/buffer_head.h>
|
||
|
|
|
||
|
|
|
||
|
|
static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
|
||
|
|
|
||
|
|
unsigned long ext3_count_free (struct buffer_head * map, unsigned int numchars)
|
||
|
|
{
|
||
|
|
unsigned int i;
|
||
|
|
unsigned long sum = 0;
|
||
|
|
|
||
|
|
if (!map)
|
||
|
|
return (0);
|
||
|
|
for (i = 0; i < numchars; i++)
|
||
|
|
sum += nibblemap[map->b_data[i] & 0xf] +
|
||
|
|
nibblemap[(map->b_data[i] >> 4) & 0xf];
|
||
|
|
return (sum);
|
||
|
|
}
|